Linear growth in homozygous β-thalassemia and β-thalassemia/hemoglobin E patients under different treatment regimens

Abstract

The effects on linear growth and development among thalassemic patients under different treatment regimens were compared. Twelve homozygous β-thalassemia (homozygous β-thal) and 36 β-thalassemia/Hb E (β-thal/Hb E) were studied longitudinally between 1977 and 1998. Eighteen cases (10 homozygous β-thal and 8 β-thal/Hb E) received hypertransfusion with iron chelation by desferrioxamine. Another 30 cases (2 homozygous β-thal and 28 β-thal/Hb E) were given a low transfusion (depending on their clinical requirement). Their heights were measured serially and are presented as a standard deviation score (SDS). There was no significant difference in initial basic hematological data and ferritin levels between either group. However, the hypertransfused group, seemed to be clinically more severely affected than the other group as evidenced by early age at initial transfusion, the early onset of anemia and diagnosis and also their large acquired iron load after a period of transfusion. The average height SDS of the hypertransfused patients was within the 50thpercentile ± 1 SD during the first decade of life in both sexes and both genotypes. Whereas, in patients who were transfused infrequently, the SDS was always below the -1 SD and decreased gradually. In severe β-thal/Hb E cases, their growth SDS showed no difference from those with homozygous β-thal. Normal linear growth in those with homozygous β-thal and severe β-thal/Hb E was only seen in the group that underwent hypertransfusion and this regimen contributed to normal growth during the first ten years of life. However, adequate iron chelation and hormonal treatment in these patients were also required in order to achieve normal adult height.